Carp::carp("LWP::UserAgent->use_alarm(BOOL) is a no-op")
	if @_ > 1 && $^W;
    "";
}


sub clone
{
    my $self = shift;
    my $copy = bless { %$self }, ref $self;  # copy most fields

    delete $copy->{handlers};
    delete $copy->{conn_cache};

    # copy any plain arrays and hashes; known not to need recursive copy
    for my $k (qw(proxy no_proxy requests_redirectable)) {
        next unless $copy->{$k};
        if (ref($copy->{$k}) eq "ARRAY") {
            $copy->{$k} = [ @{$copy->{$k}} ];
        }
        elsif (ref($copy->{$k}) eq "HASH") {
            $copy->{$k} = { %{$copy->{$k}} };
        }
    }

    if ($self->{def_headers}) {
        $copy->{def_headers} = $self->{def_headers}->clone;
    }

    # re-enable standard handlers
    $copy->parse_head($self->parse_head);

    # no easy way to clone the cookie jar; so let's just remove it for now
    $copy->cookie_jar(undef);

    $copy;
}


sub mirror
{
    my($self, $url, $file) = @_;

    LWP::Debug::trace('()');
    my $request = HTTP::Request->new('GET', $url);

    if (-e $file) {
	my($mtime) = (stat($file))[9];
	if($mtime) {
	    $request->header('If-Modified-Since' =>
			     HTTP::Date::time2str($mtime));
	}
    }
    my $tmpfile = "$file-$$";

    my $response = $self->request($request, $tmpfile);
    if ($response->is_success) {

	my $file_length = (stat($tmpfile))[7];
	my($content_length) = $response->header('Content-length');

	if (defined $content_length and $file_length < $content_length) {
	    unlink($tmpfile);
	    die "Transfer truncated: " .
		"only $file_length out of $content_length bytes received\n";
	}
	elsif (defined $content_length and $file_length > $content_length) {
	    unlink($tmpfile);
	    die "Content-length mismatch: " .
		"expected $content_length bytes, got $file_length\n";
	}
	else {
	    # OK
	    if (-e $file) {
		# Some dosish systems fail to rename if the target exists
		chmod 0777, $file;
		unlink $file;
	    }
	    rename($tmpfile, $file) or
		die "Cannot rename '$tmpfile' to '$file': $!\n";

	    if (my $lm = $response->last_modified) {
		# make sure the file has the same last modification time
		utime $lm, $lm, $file;
	    }
	}
    }
    else {
	unlink($tmpfile);
    }
    return $response;
}


sub _need_proxy {
    my($req, $ua) = @_;
    return if exists $req->{proxy};
    my $proxy = $ua->{proxy}{$req->url->scheme} || return;
    if ($ua->{no_proxy}) {
        if (my $host = eval { $req->url->host }) {